Hi Wilson KOSSOUHO,

First you need to check you are at the correct odoo directory or not to start the server.
For that Just type cd /home/wilson/workspace/odoo and hit the enter in terminal. Then try the below server path

    python ./odoo-bin --addons-path=addons,/home/wilson/workspace/my_addons/

No need to add the path "/home/wilson/workspace/odoo/odoo/addons" and make sure the "/home/wilson/workspace/my_addons/" path has the addon modules in it not a sub directory, Means it will contains the sub directory then you need to give the sub directory path too.

just like :
    python ./odoo-bin --addons-path=addons,/home/wilson/workspace/my_addons/sub_directory/

Hope it will work for you. Please up Vote.